It is in fact nearly impossible to start a social site of any kind, be it news or dating, without fake users in the beginning. Look, even reddit started that way:
Politics isn't excluded from it either. The computer security industry's biggest patron happens to be big business and government. When this was revealed I wasn't at all surprised:
Creating multiple accounts is easy. Teams working full time can appear to be a much larger crowd, and with enough technical resources it can be very difficult for a site admin to detect. Astroturfing is just a form of social engineering (in hacker context) so obviously the computer security industry is going to build frameworks to make it more effective.
There's an entire industry which you may have heard of, called SEO, that is essentially astroturfing.